Accessory uses and buildings are concepts central to zoning decisions.

Sechelt (District of) v. Cutlan, 2008 BCCA 368, is a case that deals with an accessory use and building in the form of a bed and breakfast contained in a separate small building on the lot:

[6] The Cutlans says that the judge erred in using the bylaw’s definition of the term “accessory to” to assist him in determining the meaning of the expression “accessory building”. While the chambers judge did note the definition of the term “accessory to” and did determine that the proper interpretation of the term “accessory building” was consonant with that definition, I do not find that he approached the task of statutory interpretation improperly by conflating the two terms. Rather, he considered the ordinary meaning of the term “accessory building”, and also examined the statutory context in which the term is used. I agree with his discussion of the concept of “accessory building” in the bylaw, and with his conclusion that the term “accessory building” does not contemplate the use of the building as sleeping accommodations.

[7] An examination of the structure of the bylaw and its specific terms dealing with dwelling units strengthens my view that the chambers judge was correct in this regard. The bylaw defines a “dwelling unit” as “a suite of rooms which provide accommodations for one family, has its respective entrance, and contains sleeping, toilet facilities and not more than one set of cooking facilities.” The word “family” is given a broad, inclusive, definition in the bylaw.

[8] The chambers judge found that that the presence of sleeping accommodations in the “accessory building” would bring it within the definition of a “dwelling unit”. I agree with that conclusion. The “accessory building” is a suite of rooms, with its own entrance and with toilet facilities. The Cutlans argue that because it does not contain cooking facilities, it cannot be a “dwelling unit”. The chambers judge correctly rejected this argument, holding that the definition does not require that a “dwelling unit” have cooking facilities; it merely prohibits a dwelling unit from having more than one set of cooking facilities.

[9] Where the bylaw intends dwelling units of various types to be permitted in zones, it does so explicitly. Given the general structure and context of the bylaw, it is, I think, clear that the term “accessory building” was not intended to include any building that is a “dwelling unit.”

There you have it. Accessory buildings are not to be used for sleeping purpose. Even though the decision turns on the language of the bylaw at hand, the underlying reasoning is generally applicable.